I suspect it has something to do with pam. Have you etc-update'd? What version of pam and other authentication programs do you have installed?_________________Intel Core i7 2700K@ 4.1GHz/HD3000 graphics/8GB DDR3/180GB SSDWhat am I supposed to be advocating?

I'm getting the exact same thing, I cannot log in at all as user, I didn't try root (I assume the same would happen).
I'm not sure when this happened though I was just checking I could still boot up with openrc after the last update promoted for some udev-init-scripts changes, been using sysd for a few months. Running ~amd64.